• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2232-2237
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• 2007

Steam reforming and catalytic reforming of $CH_4$ conversion to produce synthesis gas require both high temperatures and high pressure. Non-thermal plasma is considered to be a promising technology for the hydrogen rich gas production from methane. In this study, three phase AC GlidArc plasma system was employed to investigate the effects of gas composition, gas flow rate, catalyst reactor temperature and applied electric power on the $CH_4$ and $H_2$ yield and the product distribution. The studied system consisted of three electrode and it connected AC generate power system different voltages. In this study, air was used for the partial oxidation of methane. The results showed that increasing gas flow rate, catalyst reactor temperature, or electric power enhanced $CH_4$ conversion and $H_2$ concentration. The reference conditions were found at a $O_2$/C molar ratio of 0.45, a feed flow rate of 4.9 ${\ell}$/min, and input power of 1kW for the maximum conversions of $CH_4$ with a high selectivity of $H_2$ and a low reactor energy density.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.11
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• pp.942-948
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• 2007

Popular techniques for producing hydrogen by converting methane include steam reforming and catalyst reforming. However, these are high temperature and high pressure processes limited by equipment, cost and difficulty of operation. Low temperature plasma is projected to be a technique that can be used to produce high concentration hydrogen from methane. It is suitable for miniaturization and fur application in other technologies. In this research, the effect of changing each of the following variables was studied using an AC GlidArc system that was conceived by the research team: the gas components ratio, the gas flow rate, the catalyst reactor temperature and voltage. Results were obtained for methane and hydrogen yields and intermediate products. The system used in this research consisted of 3 electrodes and an AC power source. In this study, air was added fur the partial oxidation reaction of methane. The result showed that as the gas flow rate, the catalyst reactor temperature and the electric power increased, the methane conversion rate and the hydrogen concentration also increased. With $O_2/C$ ratio of 0.45, input flow rate of 4.9 l/min and power supply of 1 kW as the reference condition, the methane conversion rate, the high hydrogen selectivity and the reformer energy density were 69.2%, 32.6% and 35.2% respectively.

• Transactions of the Korean hydrogen and new energy society
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• v.18 no.2
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• pp.132-139
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• 2007

Popular techniques for producing synthesis gas by converting methane include steam reforming and catalyst reforming. However, these are high temperature and high pressure processes limited by equipment, cost and difficulty of operation. Low temperature plasma is projected to be a technique that can be used to produce high concentration hydrogen from methane. It is suitable for miniaturization and for application in other technologies. In this research, the effect of changing each of the following variables was studied using an AC Glidarc system that was conceived by the research team: the gas components ratio, the gas flow rate, the catalyst reactor temperature and voltage. Glidarc plasma reformer was consisted of 3 electrodes and an AC power source. And air was added for the partial oxidation reaction of methane. The result showed that as the gas flow rate, the catalyst reactor temperature and the electric power increased, the methane conversion rate and the hydrogen concentration also increased. With $O_2/C$ ratio of 0.45, input flow rate of 4.9 l/min and power supply of 1 kW as the reference condition, the methane conversion rate, the high hydrogen selectivity and the reformer energy density were 69.2%, 36.2% and 35.2% respectively.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.11
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• pp.103-112
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• 2011

This paper is tried to analysis the optical emission spectroscopy related to the position of inductive load coil and flow rates of methane and oxygen in the RF inductive plasma process. According to the position of load coil, peak of $H_{\alpha}$, $H_{\beta}$, and CH were appeared strongly at the middle position of the coil and it decreased both direction. The electron temperature was approximately 0.9[eV] at that position. Emission intensities of $H_{\alpha}$, $H_{\beta}$, and CH increased linearly by increasing input power. In addition, intensities of $H_{\alpha}$ and $H_{\beta}$ increased by increasing the flow rate of oxygen. It might be ascribed that the oxygen species were bonded with $C_nH_m$ by suppressing the combination with hydrogen atoms. Consequently, the optimal position of the inductive coil is decided to the intermediate position between 4th and 5th turns, the wanted carbon thin-film is possible to deposit by controlling flow rates of methane and oxygen.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.2
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• pp.46-56
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• 2013

The test facility with hot-air supply system is required to develop transpiration cooling materials and experimentally evaluate its performance. In the study, the facility consists of an arc-plasma generator, plenum chamber suppling cold air, and test section was designed and an internal flow analysis was executed. From CFD results, it was confirmed that the designed plenum chamber thermally safeties and ideally mixes with plasma gas and cold air in the chamber. In addition, validity of design for supplying homogeneous flow to the test section was confirmed by this analysis.

• The Journal of Engineering Geology
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• v.32 no.1
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• pp.127-142
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• 2022

This study explored the fluid transfer characteristics of simultaneous pneumatic blasting, plasma blasting, and vacuum suction (the PPV method), and assessed their effect. Chemical oxidation-an established soil remediation method-was compared as a control. Electrical resistivity surveys found that PPV reduced resistivity by about 1.5-2.5 times compared with the control group, indicating that it increased the diffusion of fluid between the injection and suction wells. Injection and suction tests comparing the injection flow rate, initial suction flow rate time, and suction flow rate showed that the PPV method offered an improvement over the existing method. Slug tests revealed that PPV increased the permeability coefficient by a greater amount than that by the control method. This study qualitatively and quantitatively confirmed that the PPV method clearly improves injection and suction efficiency by accelerating cracks in the ground and improving water permeability compared with the established chemical oxidation method.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.29-30
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• 2009

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.29 no.6
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• pp.359-364
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• 2019

The suspension plasma spraying is a modification of conventional plasma spray techniques that has been developed to overcome the challenge of using fine particles in plasma spray processes. In this study, microstructure developments and mechanical property of yttrium oxide (Y₂O₃) coatings prepared by the suspension plasma spray coating technique have been investigated to determine the effect of processing parameters including plasma gun current and total gas flow. The results showed that a highly dense Y₂O₃ coating having low porosity of 0.2 vol% without any lamellar structures can be achieved at the optimum condition of gun current 200 A and total gas flow 220 L/min.

• Journal of Adhesion and Interface
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• v.8 no.3
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• pp.1-8
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• 2007

An atmospheric plasma pre-treatment method was applied to polyurethane foam to improve its contact angle and adhesion. In order to investigate the optimum reaction condition of plasma treatment, type of reaction gas (nitrogen, argon, oxygen, air), rate of gas flow (30~150 mL/min), and reaction time (0~30 sec) were examined in a plate plasma reactor. Also, the effects were compared to those of a conventional vacuum plasma pre-treatment system. The result of the surface modification with respect to the treatment procedure was characterized by using SEM and ATR-FTIR. Due to a decrease of the contact angle of polyurethane foam, the greatest adhesion strength was achieved at a flow rate of 100 mL/min and at a reaction time of 10s for N2 gas. Consequently, the atmospheric plasma treatment reduced the contact angle of the polyurethane foam and also resulted in the improvement of the peel strength.

• Bulletin of the Korean Chemical Society
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• v.31 no.2
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• pp.335-338
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• 2010

In this study, the atmospheric plasma treatment with $He/O_2$ was conducted to modify the surface chemistry of carbon fibers. The effects of plasma treatment parameters on the surface energetics of carbon fibers were experimentally investigated with respect to gas flow ratio, power intensity, and treatment time. Surface characteristics of the carbon fibers were determined by X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), Fourier transform infrared (FT-IR), Zeta-potential, and contact angle measurements. The results indicated that oxygen plasma treatment led to a large amount of reactive functional groups onto the fiber surface, and these groups can form together as physical intermolecular bonding to improve the surface wettability with a hydrophilic polymer matrix.